1. Technical Field
The present invention relates to a self-luminescent device and an electronic apparatus.
2. Related Art
Light emitting efficiency of an organic EL element that is a self-luminescent element changes depending upon temperature. Thus, light emitting brightness changes depending upon a change of environmental temperature, a change of panel temperature caused by self-heat generation and so on. In order to deal with such changes, a technology for correcting a light emitting intensity of pixels including light emitting elements on the basis of an output of a temperature sensor is disclosed, e.g., in JP-A-2007-240812. Further, easiness to see of a screen also changes depending upon external light intensity. In order to deal with such a change, a technology for correcting a light emitting intensity of pixels including light emitting elements on the basis of an external light intensity is disclosed, e.g., in JP-A-2005-19353.
As an external light intensity and a temperature suddenly change in accordance with surrounding conditions in some cases, it is difficult to most suitably correct an image on, e.g., a display panel to be mounted on a mobile electronic device only by means of light emitting brightness control based on either one of the external light and the temperature.
Further, in a case where a display device using a self-luminescent element such as an organic EL element displays a highly bright image such as an all white image (i.e., most of pixels of a screen emit highly bright light), degradation of the pixels is accelerated resulting in a change of image quality and an increase of power consumption.
Further, if a portion of a pixel unit regularly emits light for a long time and a display of same image data continues in the portion for a long time, characteristics of pixels are severely degraded in the portion, screen burn-in occurs and a brightness difference between the portion and a surrounding area increases resulting in brightness unevenness in some cases. An organic EL display panel, e.g., installed on a vehicle displays meters while the vehicle is traveling, and displays a navigation or TV image while the vehicle is not traveling in some cases. A display area for outer fringes, gauges or numerals of the meters regularly emits light, and their displayed data is rarely changed. Thus, if the vehicle travels for a long time, characteristics of the organic EL elements of the portion which indicates the outer fringes, gauges and numerals of the meters severely change (they are severely degraded), possibly resulting in screen burn-in. If the displayed image changes from the image of the meters to a navigation or TV image after the screen burn-in occurs, brightness in the portion where the screen burn-in has been caused by the display of the meters may possibly change from a precise value beyond an allowable range, and may possibly degrade quality of the navigation or TV image which should primarily be highly precise.
Ordinary image correction technologies cannot optimize light emitting brightness in such a way, e.g., as to properly deal with all the above problems. According to at least one embodiment of the invention, e.g., light emitting brightness of a self-luminescent display device can be optimized by means of an adaptive control which deals with all the heat generation caused by environmental temperature, external light and self-emitted light, and more preferably, a compensation for degradation can be performed for screen burn-in which partially occurs.